crypto: scatterwalk - Set the chain pointer indication bit

The scatterwalk_crypto_chain function invokes the scatterwalk_sg_chain
function to chain two scatterlists, but the chain pointer indication
bit is not set.  When the resulting scatterlist is used, for example,
by sg_nents to count the number of scatterlist entries, a segfault occurs
because sg_nents does not follow the chain pointer to the chained scatterlist.

Update scatterwalk_sg_chain to set the chain pointer indication bit as is
done by the sg_chain function.

Cc: [email protected]
Signed-off-by: Tom Lendacky <[email protected]>
Signed-off-by: Herbert Xu <[email protected]>
(cherry picked from commit 41da8b5)

Author: tlendacky

include/crypto/scatterwalk.h

@@ -36,6 +36,7 @@ static inline void scatterwalk_sg_chain(struct scatterlist *sg1, int num,
 {
 	sg_set_page(&sg1[num - 1], (void *)sg2, 0, 0);
 	sg1[num - 1].page_link &= ~0x02;
+	sg1[num - 1].page_link |= 0x01;
 }
 
 static inline struct scatterlist *scatterwalk_sg_next(struct scatterlist *sg)